To date, it has been known that the kinetic energy of the vehicle can effectively be utilized, by mounting in an electric vehicle an electric-controller in which a power storage unit is integrated with an inverter that drives a motor of the electric vehicle, storing in the power storage unit superfluous regenerative electric power produced when the vehicle is braked, and utilizing the stored power when the vehicle is accelerated or when an overhead line voltage is lowered (e.g., Patent Document 1). In addition, the power storage unit is formed of a power storage device such as a secondary battery, an electric double-layer capacitor, or the like.
In order to obtain electric power that is large enough to drive an electric vehicle, the electric power accumulated in the power storage unit mounted in such an electric-vehicle controller configured as described above becomes a large quantity ranging from several KWh to several hundreds KWh. Accordingly, the power storage unit is required to store large energy, and the electric vehicle travels with such large energy stored. Therefore, there has been a problem that, in the case where an external factor such as a collision exerts external force or impact on the electric-vehicle controller and the inner circuit of the electric-vehicle controller is damaged, the energy stored in the power storage unit is discharged, whereby a great deal of heat or electromagnetic force further damages the electric-vehicle controller and the electric vehicle.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2003-199204